Hi there I own a honda cbr600f 1990. It's been smoking alot can anyone help me out.
Cleaned carbs. But 2 cylinders are running way richer than the other two which are lean.
All coils and wires are within ohm spec. Battery fully charge. Isles rough and has had rejected by previous owner.

 

Hi which 2 cylinders are running rich , and have you had the valve clearances done

 

Hi there, the 2 non chain side cylinders and yes the valve clearances are also in spec with haynes manual.

 

Then I think its unlikely to be coils, as you know left coil 1-4 and right coil 2-3, didn't see that picture in first post , that plug is either running very lean or starved of fuel to that cylinder, looks like carbs might need to come off , but before you do that, can you test the two fuel bowls for fuel, attach a tube onto the bowl drain outlet to collect any fuel , then undo the screw on the bottom of the bowl

 

Yes I've done the gas bowl test.. pretty similar to each other but the one running rich was fuller than the rest which were pretty close to each others. Got a compression tester coming today fingers crossed so will post the results later on. Also some new spark plug coming. The 2 cylinders running rich and are very yellow spark plug is maybe because I have it beans to you as the systems out as it was sat for many years from previous owner

 

 

Good looking bike matey ,and worth getting it running right, maybe as your doing a compression test might be worth whipping the carbs off ,giving them a good clean and checking the jet sizes

 

I've stripped her down again the jets are 38 and 110 I think there stock at 35. 105 not too sure.. so do I need more air like an exhaust mod and air filter to composite I'll post more pictures later 😉😅

 

Correct matey should be 35 ,105, but I'd get the carbs cleaned, maybe rejet , what filter is in ? and sync

 

Stock filter.. crappy one 😎 and I've got a sync tool will do that on saturday